U.S. Pat. No. 3,801,227 of Shozo Nakayama discloses a multi-piston, double acting, single swash-plate refrigerant gas compressor having a pair of horizontal axially aligned cylinder blocks forming a combined block.
The compressors of this type are provided with an internal arrangement for distributing oil lubricant to movable parts or elements of such compressors, such as pistons, bearings and shoes in contact with the swash-plate. However, it has recently been found that such a prior internal arrangement is incomplete for the following reason.
When the compressor is stopped, lubrication oil flows into the reservoir by gravity and moving elements become dry. Also the refrigerant gas has no suspended oil particles therein. At the moment of starting the compressor, said dry gas is sucked into the compressor, and passes over the surfaces of said moving elements without any lubricating thereof, so they are susceptible to damage due to overheating.